Strip filename

kalyanrajsista has asked for the wisdom of the Perl Monks concerning the following question:

Hello all

I'm trying to strip off offensive characters from filename with the below snippet written long back (not by me) and is not doing what exact I want.

use strict;
use warnings;

print cleanfilename('abcdefghijklmnopqrstuvwxyz.xml');

sub cleanfilename {
    my ($ans) = @_;

    $ans =~ y/\/\\[]{}()?*#$^&@*;''""``<>%|//d;
    $ans =~ y/[[:space:][:cntrl:]]//d;
    
    return $ans;
}
[download]

Output

bdfghijkmoquvwxyz.xm
[download]

Comment on Strip filename Select or Download Code

Replies are listed 'Best First'.
Re: Strip filename by almut (Canon) on Dec 22, 2009 at 09:01 UTC
`$ans =~ y/[[:space:][:cntrl:]]//d;` As the docs say (--> 'Note that "tr" does not do regular expression character classes such as "\d" or "[:lower:]"'), character classes cannot be used with `tr///` (which is the same as `y///`). Use regex substitution (`s///`) instead.	[reply] [d/l] [select]
Re: Strip filename by Ratazong (Monsignor) on Dec 22, 2009 at 08:57 UTC
you are "escaping" / and \ (by using `\/ \\`) ... but what about ( ) $ ? ..... - they all have special meanings! Try escaping them, too! HTH Rata	[reply] [d/l]
Re^2: Strip filename by kalyanrajsista (Scribe) on Dec 22, 2009 at 11:48 UTC
Actual culprit is below line which is replacing some of the characters like 'l' or 'c' with null values. Is there any alternative for this... `$ans =~ y/[[:space:][:cntrl:]]//d;` [download]	[reply] [d/l]
Re^3: Strip filename by almut (Canon) on Dec 22, 2009 at 12:09 UTC
Is there any alternative for this Yes: `$ans =~ s/[[:space:][:cntrl:]]//g;`	[reply] [d/l]
Re: Strip filename by Anonymous Monk on Dec 22, 2009 at 18:04 UTC
Another idea is specify only allowed characters, like ascii letters and numbers dash and underscore `s![^abcdefghijklmnopqrstuvwxyz0123456789_\-]!!gi` [download] or create sha1 hash of the file and use that as the filename `$ perl -MDigest -le " $sha256 = Digest->new(q!SHA-256!); $sha256->add +file( *STDIN ); print $sha256->hexdigest " < test a505e6720df306ab46a6b24c458b8b77b60bffa18d831f4796ba1b736bb44c6c` [download]	[reply] [d/l] [select]